Radiospeaker



July 22, 1930. R. 'r. KINGSFORD RADIO SPEAKER Filed D60. 16, 1926 11 ATTORNEY.

Patented July 22, 1930 UNITED: STATES PATENT OFFICE RUSSELL T. KINGSFORD, F W'YNCO'I'E, PENNSYLVANIA, ASSIGNOR TO ATWATEB KENT MANUFACTURING COMPANY, OF IHILADELPHIA, PENNSYLVANIA, A CORPORA- 'fION OF PENNSYLVANIA BADIOSPEAKER Application nled necember 16, 1926. Serial No. 155,159.

My invention relates to telephonic apparatus, and particularly to amplifying telephones, loud speakers or radio speakers, utilized in connection with radio receiving apparatus.-

In accordance with my invention, the airvibrating diaphragm or tympanum is shield ed or protected by a housing structure conforming generally in configuration with that of the diaphra m, and more particularly, the

aforesaid diap ragm is conical and of relatively large area and is dis o'sed within a generally conical housing, w ereby, should the instrument be overturned, the diaphragm is protected from injury.

Further in accordance with my invention. the air-vibrating diaphragm or tympanum of paper, metal, or other suitable material, preferably of large area or diameter and pref rably conical, has its peripheral edge spaced from a protecting ring-like housing and is supported solely b a member substantially non-flexible in a direction coinciding with the gravitational plane of the diaphragm and of relatively great flexibility in a plane substantially at right angles to said gravitational plane. 1

My invention resides in the apparatus and features of construction of the character hereinafter described and claimed.

For an understanding of some of the forms my invention may take, reference is to be had to the accompanying drawings in which:

Figure 1 is 'a vertical sectional view of apparatus constructed in accordance with my invention.

Figs. 2 and 3 are, respectively, rear and front views of the structure shown in Fi 1.

Fig. 4 is a horizontal sectional view 0 the apparatus shown in Fig. 1.

Fig. 5 is an enlarged vertical sectional view of a part of the apparatus shown in Fig. 1.

Fig. 6 is a horizontal sectional view taken on the line 66 of Fig. 1 looking in the direction of the arrows.

Referring to the drawings, 1 is a stand or supporting member to which is suitably secured, as by 'bolt 2, the base 3 of a conical housing structure comprising the ring or annulus 4 from which inwardly and at an angle fastening elements serving to unite frames 7, 7 and pole pieces 8 and secure .the combined structure to casing6.

When the casing 6 is of magnetic material, screws 9 should be non-magnetic in character, as brass or the like. In the event that casing 6 is of non-magnetic material, screws 9 may be either magnetic or non-magnetic, as found desirable.

Fixed between the frames 7, 7 by the bolt 10 is one end of the armature bar or reed 11 whose freeend is received in the air gap between theaforesaid pole pieces 8 and maintained in adjusted position with respect thereto by adjustin screws 12 threaded through the frames 7, and co-acting with opposite faces of the reed 11. Disposed between the frames 7, 7 for. holding them in suitable spaced relation, at the end thereof opposite the bolt 10 is a spacing washer or element- 13 through which and the plates 7, 7 passes a bolt 14, while adjacent the bolt 10 on each side of the reed 11 are spacing washers, not shown. I

the combined thickness of which and the reed 11 is substantially the same as that of spacing washer 13 and also of the pole pieces 8.

The magnet system M may be utilized to actuate any shape and tigpe of air-vibrating or diaphragm structure other suitable material. Preferably, however, diaphragm D is conical and of relatively of paper, metal or largearea, as six inchesor'more in diameter or its equivalent, and one which for both axial and transverse vibration throughout and which is entirely free to v1- brate at its extreme periphery at the frequency and with the am litude of vibrations transmitted therethroug from its apex or center.

As shown, particularly in Figs. 1, 4 and 5,

is unrestricted diaphragm D, at a suitable distance from its edge has imparted thereto a stiffening bend and one or both sides of its extreme peripheral edge may have a layer 16 of felt or similar fabric applied thereto.

Fol the reception of the peripheral edge of the diaphragm D, the ring or annulus 4 preferably is circumferentially grooved as indicated at 17, Figs. 1, 4: and 5.

Spaced from the ring 4 and its groove 17 to form a housing for said peripheral edge of the diaphragm is the second ring or annulus 18 suitably secured to the ring l, preferably by utilizing spacing washers or elements 19 in conjunction with screws 20.

The diaphragm D at its apex may be provided with the inner and outer conical facing washers 21 and 22, the latter forming a seat for the angular arms of the thereto-secured bracket 23 terminating in a pocket for the reception of the end of a member 24 extend-' ing laterally of the vibratory armature or reed 11 and secured in the aforesaid pocket by a bolt 25 or similar fastening element.

It will be understood that while I have shown the diaphragm made in the form of a symmetrical circular cone, other types of cones may sometimes be used to advantage, such as oval, eccentric or pyramidal, and I do not limit myself t o any one type.

As illustrated in my aforesaid application, the reed or armature bar 11 is disposed in a plane extending substantially at right angles to the gravitational plane of the diaphragm. Inasmuch as the armature bar is mounted for pivotal or oscillatory movement, a to-and-fro movement is imparted to the end of member 24 in the longitudinal plane of said armature bar. Should the member 24. be non-flexible, such. for example, as is constituted by the rigid pin or bar of the prior art, the diaphragm would be given a transverse bodily to-and-fro movement with resultant distorted or imperfect sound reproduction, to eliminate which member 24 should be so constructed as to be flexible in the plane wherein occurs the aforesaid to-and-fro movement, whereby, due to its inertia, the diaphragm D partakes but slightly, if at all. of the to-andfro movement of the end of the thereto connected supporting member 24. Atthe same time, member 24 should be so constructed as to be substantially non-flexible in the direction of the gravitational plane oft-he diaphragm D wherebythe same may be supported without flexing or bending said member 24. In accordance with this phase of my in- I structed of paper,

vention, the member 22 may be of substantially greater breadth than thickness and so disposed with respect to the diaphragm D that the weight is carriedin the direction of breadth rather than width.

Diaphragms forming a part of the loud speakers of the prior art are usually conor similar material easily structure just mentioned would take said diaphragm and comprising fractured should the instrument overturn.

By my invention, however, the danger of such mischance is to a substantial degree eliminated due to the fact that the ring 4, ribs 5 and casing 6 form-ahousing of generally conical shape for the diaphragm D. Thus, should the instrument as viewed in Fig. 1 fall toward the right, some part of tge t e shock and ordinarily prevent damage to the diaphragm. Or. should the instrument fall toward the left, the ring 18 would intervene, and if subjected to an end-on fall one or both of the rings 4 and 18 would absorb the impact. The casing 6, besides functioning to thus prevent damage to the diaphragm, also functions as an enclosure for the magnetic system M.

The housing structure comprising the ring 4, ribs 5 and casing 6, as well as the ring 18, may be constructed of such material as may be found desirable. Ordinarily, such structures should be cast iron castings or preferably die castings.

The ring 4 or the lowermost rib 5, preferably the latter, may be provided with a perforation 26 through whichpasses a cable 27 including the conductors leading to the coil associated with the magnetic system and traversed by the sound-representing current.

It may also be desirable to provide an opening 28 in the casing 6 through which may be passed a tool for adjusting one of the screws 12 after the apparatus is assembled. By so doing, the air gap between the pole piece exten. ons of the pole pieces 8 and the free end 0 reed 11 may be adjusted to-suit the characteristics of the particular apparatus with which'the herein disclosed device is to be used.

\Vhat I claim is 1. The combination with a. conical dia phragm of large area and having a freely vibrating periphery, of substantially nontlexible structure overlying the convex side of a member conforming with and closely spaced from its peripheral edge.

2. The combination with a conical diaphragm of large area, of a magnet system dis- 1 posed adjacent the apex of said diaphragm. and a casing within which said magnet system is disposed presenting an open wall 0 area less than the base areaof said conical diaphragm to the convex side thereof.

3. The combination with a conical diaphragm of large area and having a freely vibrating periphery, of a magnet system disposed adjacent the apex of said diaphragm. and a housing structure comprising a ringshaped circumferentially-grooved member spaced from the periphery of said diaphragm, ribs extending toward the center of said member and overlying the convex side of till a housing structure com rising a'ring-sh'aped 7 spaced from the periphery o said diaphragm and a casing within which said magnet system is confined.

4. The combination with a conical diaphragm of large area and having a freely virating periphery, of a magnet system disposed adjacent the apex of said diaphragm,

member spaced from t e periphery of said diaphragm, ribs extending toward the center of said member and overl ing the convex side of said diaphragm an a casing within which said magnet system is disposed, and a second ring-shaped member secured. in spaced relation to said first-named ringshaped member. I a

5. The combination with a loud speaking telephone including a magnet system com prising a vibratile member, a conical diaphragm of large area and having a freely vibrating riphery, and means for securing said diap ragm solely adjacent its apex to said vibratile member comprisin a member having substantially greater flexibility in one directlon than in another, of a. housing structure comprising a ring-shaped member spaced from the periphery of said diaphragm, ribs extendin toward the center of said ring-shaped mem er and overlying the convex side of said diaphragm, and a casin within which said magnet system is confine 6. The combination with a loud speaking telephone including a magnet system comprising a vibratile member a conical diaphragm of lar e area and having a freely vibrating perip ery, and means for securing said diaphragm solely adjacent its apex to said vibratile member comprising a member having substantially greater flexibili in one direction than in another, of a housing structure comprising a ring-aha member said diaphra ribs extending toward the center of said ring-shaped member out of the lane said vibratile member comp thereof and overlying the convex side said diaphragm, and a casing within which said magnet system is confined.

7. The combination with a loud speaking telephone including a magnet system com prising a vibratile member, a conical diaphragm of. lar 0 area and having .a freely vibrating perip er and means for securing said diaphragm so ely adjacent its center to a member having substantially ater flexi ility in one directon than anot er, of a housing struc ture comprising i a ring-shaped member s aced from the riphery of said ,diap ragm, ribs extenmfiilg toward the center of 881d member and over yingthe convex side of said diaphragm and a c within which said magnet system is confin and a'second disposed adjacent the apex' o 8.-The combination with a. conical diaphragm of large area and having a freely vibrating periphery, and a vibration-transange terminating in the freely vibrating periphery of said diaphragm, and a vibradon-transmitting member secured to said diaphragm adjacent the apex thereof and comprising the sole support therefor, of a housing structure comprising annular members disposed on oppositesides of and extending adjacent said flange.

10. The combination with a conical dia-.

phragm of lar e area and having a freely vibrating perip cry, of a casing on the convex side of said diaphragm, a magnet system disposed within said casing and comprising a vibration-transmittin member extending freely through said conical diaphragm substantially at the apex thereof, and structure secured to and extending inwardly from said diaphragm, attached to said member.

11. The combination with a conical diaphragm of large area, of a magnet system said dia phragm, and housing structure for said diaphragm and ma et system comprising a rin' -shaped mem r in a plane paralle to an adjacent the base of said conical diaphra rib structure extending from said mem r overlying and substantially conforming to the convex side of said conical diaphragm, and a casing enclomng said'mafignet system extending outwardly from a apex of the diaphragm and said rib structure.

RUSSELL T. KINGSFORD.

ring-shaped member secured in spaced relation to said first-named member and between which the p e r ig d r y g gaiddiaphragm is freely vibratory. 

